Artificial leg



INVENTOR 50 945 Eflai/ns April" 6 1926.

' v G. E. MARKS ARTIFICIAL'LEG Filed April 16, 1 4

TI'ORNEYr- Patented Apr. 6, 1926.

1 UNITED. STATES PATENT oFFicE.

= GEORGE E. MARKS, OF SOUND BEACH, CONNECTICUT.

ARTIFICIAL LEG.

Application filed April 16, 1924. Serial as. 706,829.

State of Connecticut, have invented certain,

new and useful Improvements in Artificial Legs, of which the following is a specification. 1 I

The invention: pertains more particularly to artificial legs for amputations below the knee, and it consists inan artificial leg having, among other features, a knee-joint which may oscillate on thev leg socket, the axis of motion preferablyybeing in theregion of the ankle. One object ofthe invention is to provide an artificial leg which will afford better accommodation for long tibial stumps and in which the socket of the leg will move with the stump and maintain continuous pressure at the places intended, thereby obviating constriction of the vascular parts back of the kneeand other uncomfortable conditions.

Customarily artificial legs for tibial stumps have knee joints riveted immovably to the leg sockets, the joints being con structed on the ginglymoid or 'unicentric In the natural knee, the knee articulation is the resultof the femur rolling on the irregular surface of the tibia, the movement being cycloidal or polycentric. V

In requiring the polycentric natural knee joint to articulate with the unicentricartificial knee joint, there follows a movement.

of the stump in the socket which induces unpleasant and painful consequences; stump slips from its bearingsand it oscillates from the frontto the rear and back to the front every time a step is taken, and when sitting the stump is influenced to recede from the front of the socket leaving a gap at the upper front edge of the socket and creating excessive pressure at the front of the lower end of the stump and also on the tissues at the popliteal area or' back of the knee joint. created at the popliteal area constrict's the blood vessels at the vascular part of the knee and hinders proper nourishment of the stump, thereby inducing swelling, congestion and laceration of the cicatices.

One purpose of my invention is to obviate the conditions just hereinbefore described by providing an artificial leg with the novel knee joint connection hereinafter described the the leg socket, as shown in Fig. 3.

links 18 are adapted to have an OSClllfttOlj The undue pressure thus.

which assures a proper yielding of the artificial leg to the varying polycentric lines of motion of the natural knee.

The invention will be fully understood from the detailed description hereinafter presented, reference'being had to the .accompanying drawings, in which I Fig. 1 is a side elevation of an artificial standing position;

Fig. 3 is a transverse section, on a larger scale, through the leg socket taken on the dotted line 33 of Fig.1, and

the wearer is in a Fig. 4 is a vertical section, on a larger scale, through a portion of the leg taken on the dotted line l- 1 of Fig. 1. I

In the drawings 10, 11, respectively, designate the leg socket and thigh corset of the artificial leg, these two features except as t The natural leg, or the remainlower end-to the leg socket 10 and extending at its upper end, above said socket, and a bar 14 connected withthe thigh corset 11 and projecting beyond the lower edge of the same and pivotally secured to theupper end of the link 153.

The links 13'at opposite sides of the leg socket 1O correspond with each other and are of metal and at their lower ends are secured by 'screws'lf) upon the polygonal ends 16 of a transverse spindle 17 confined within a stationary sleeve 18 crossing the interior of The movement, the axisof motion being at the lower ends thereof and preferably at the region of the ankle. During the oscillatory movements of rthe links 13 the spindle 1'7 turns in the sleeve 18, receiving its motion from the links and assuring uniformity of motion in said links. My invention is not limited to the specific means shown for forks the adjacent ends of the bars 14;, the links 13 and bars 14 being pivotally connected together by screws of familiar character. 1 i

Theopposite sides of the leg socket 10 are vertically grooved, as at 21, to receive portions of the links 13 and permit said links to perform their oscillatory movements between the edge walls of said grooves, said edge walls serving as stops for limiting the movements of the links and extending upwardly on diverging lines. i'kpproximately near the upper end of the leg socket 10 I provide thereon an encompassing leather band 22 having at opposite sides of the socket, the loops 23 slit and lmlged outwardly from said band and receiving and confining the upper portions of the links 13 without interfering with the oscillatory motion of the links. The loops 23 confine the upper portions of the links 13 in correct relation to the sides of the leg socket, and during their t oscillatory movements said links rub against the hand 22 above and below the loops 23 instead of against the surface of the leg socket. The loops 23 also serve as means for limiting the extent of movement of the links 13.

The bars 14 are practically straight except at their exposed ends where they are slightly curved adjacent to the upper forked ends of the links 13, as shown, and said bars at their body portions are riveted to the thigh socket and concealed within elongated leather pockets 2 1 securely fastened to opposite sides of the thigh corset 11 and in line with the length thereof.

In the use of the artificial leg having its members connected by the links 13 on the leg socket and bars 14 on the thigh socket, the human leg may have its natural movements both when the wearer is walking or taking a sitting position or arising to a standing position, without restraint and therefore without creating unpleasant or detrimental pressure either at the front of the lower end of the stump or at the popliteal area. The oscillatory links 13 by being pivoted at their lower ends on the leg socket yield to the varying polycentric lines of motion in the natural knee, and hence the stump may be firmly held in the leg socket, without, discomfort and with advantage to the wearer of the, leg; My inventionefficiently provides in the artificial leg a polycentric knee joint adapted to harmonize with the polycentric joint ofthe natural knee and does so in a superior manner and by means which simplify the artificial leg construction, eliminating many rivets and other usual features.

The links 13 pivoted at. their lower ends in the region ofthe ankle are features .of special importance in carrying out my invention. 7 v

hat I claim as my invention and desire to secure by Letters-Patent, is:

1. An artificial leg, comprising. a leg socket, a thigh member, links extending lengthwise of the leg socket and pivoted at their lower ends at opposite sides of'the leg socket for an oscillatory movement with respect to the leg socket, and bars on opposite sides of the thigh member pivotally secured to the upper ends of the links, whereby. are provided jointed means connecting the socket and thigh member at the knee;

2. An artificial leg as claimed'in Claim 1, in which the means securing the lower ends of said links to the socket member comprise a transverse spindle mounted in said member and having polygonal ends on which the lower ends of the links fit and screws retaining the links on said ends, said spindle assuring uniformity of motion in said links.

3. An artificial leg as claimed in claim 1, in which the socket member has vertical grooves on its opposite sides receiving said links, said grooves having upwardly diverging edge walls.

4. An artificial leg as claimedin claim 1, lL which. the socket member has approximate ly nearits upper end an encompassing band formed on opposite sides wit-h outwardly bulged loops through which saidlinks are strung and which retain the upper end portions of the links in proper relation to the sides of the socket member.

Signed at New York city, in the county of New York and State of New York, this 14th day of April, A. 'D. 1924;.

GEORGE E. MARKS. 

